​​​​
​
CASE STUDY
​
Hashimoto’s Thyroiditis, Chronic Fatigue & Anxiety — A Functional Medicine Recovery Story
​​​
​
Who This Is For?

If you have been living with crushing fatigue, anxiety, low self-confidence, and a persistent sense of apathy — and feel like nothing has truly worked — this case study is for you.

This is the story of how C.B., a woman in her mid-forties, found profound and measurable relief from Hashimoto’s thyroiditis, chronic exhaustion, and anxiety through a root-cause functional medicine approach — achieving an MSQ symptom score from 40 to 4 over ten months. 

If you are looking for functional medicine for Hashimoto’s thyroiditis, a nutritional therapist for chronic fatigue and anxiety, or a root-cause approach to autoimmune thyroid disease  — read on.

The Journey

Presenting Symptoms & Goals

C.B. came to Paul having lived with a debilitating cluster of symptoms across multiple systems for many years, including:
 

• Profound tiredness and fatigue that persisted regardless of rest

• Apathy — a loss of motivation and engagement with daily life

•   Anxiety — including difficulty grasping and processing concepts at work, and heightened reactivity in busy social situations

•  Low self-confidence and poor self-esteem, long-standing in nature

•  Constipation dating from infancy — a lifelong pattern of sluggish gut motility

• Eczema on the stomach and underarms, worsening with the menstrual cycle

• Heightened chemical sensitivity — strong reactions to perfumes, colognes, and vehicle fumes

• lated deterioration in energy and overall resiliencePerimenopause-re

What C.B. was seeking was not just symptom relief.

 

She wanted to understand the underlying reason her body had been struggling for so long — and to find a path back to the energy, clarity, and confidence that felt like they had slipped steadily away.

Background

C.B.’s health journey was a long one. Digestive difficulties had been present since childhood, thyroid irregularities had been identified in her early thirties — when conventional thyroid medication provided little meaningful improvement in energy — and a significant history of chronic stress and psychosocial strain had placed a sustained load on her nervous system and HPA (hypothalamic-pituitary-adrenal) axis over many years. This background is clinically significant: chronic nervous system dysregulation is both a driver and a consequence of autoimmune activity, and without addressing it, thyroid hormone alone rarely resolves the full picture.

She had also experienced a history of chronic candida overgrowth in her twenties and ongoing immune hypersensitivity — both markers of a gut-immune system under long-term stress. By the time she came to Paul, everything about the previous year had felt “very difficult.” The thyroid, the gut, the nervous system, the immune system: all were connected, and all needed to be seen together.

Key Testing & Clinical Insights

Rather than addressing symptoms in isolation, a comprehensive functional medicine assessment was carried out at the start of the programme to identify the underlying drivers.

Full Thyroid & Autoimmune Antibody Panel

This goes far beyond the single TSH test offered in standard care, measuring the complete picture of thyroid hormone production, conversion, and autoimmune activity to identify exactly where the system is breaking down.

TPO Antibodies (Thyroid Peroxidase): At the initial assessment, TPO antibodies were 291 IU/mL — more than thirty times above the reference range of ≤9. This is the defining finding of Hashimoto’s thyroiditis: the immune system mounting a sustained, damaging attack on its own thyroid tissue. High antibody levels correlate with thyroid inflammation, impaired hormone output, fatigue, cognitive fog, anxiety, mood disruption, and skin reactivity — every one of C.B.’s core complaints. Over the course of the programme, antibodies fell progressively: 291 → 111 → 79 → 72 — a remarkable and meaningful reduction reflecting genuine immune modulation, not simply symptom masking. 

 

 

 

​​

 

 

TSH (Thyroid Stimulating Hormone): TSH was severely elevated at 32.81 mU/L (reference: 0.27–4.2) at the initial blood draw — indicating the brain was desperately signalling the thyroid to produce more hormone because the gland, under autoimmune attack, could not keep up. Despite this, conventional management had not adequately addressed the root cause. TSH progressively improved across the programme, reflecting the combined effect of thyroid glandular support, immune modulation, and nutrient repletion.

A TSH this elevated means the brain is sending urgent distress signals to a thyroid that cannot adequately respond — a hallmark of Hashimoto’s-driven hypothyroidism. This result explained C.B.’s profound fatigue and cognitive symptoms directly.

Free T4, Total T3 & Free T3: Free T4 was low at 8.8 pmol/L (reference: 10–28.2), confirming insufficient thyroid hormone output. Interestingly, Total T3 showed some elevation at 2.71 nmol/L, which — alongside the very high TSH — indicated a complex pattern of under-replacement, conversion issues, and ongoing autoimmune interference. Free T3 was within range at 4.2 pmol/L. This layered picture — which standard TSH-only testing would have missed entirely — was essential to designing a programme that actually addressed the full thyroid picture.

 

 

Ferritin (Iron Storage)
Ferritin measures how much iron the body has in reserve. Even without clinical anaemia, low ferritin is a significant driver of fatigue, poor thyroid function (iron is required for the enzyme that converts T4 to active T3), poor concentration, and mood instability.

Finding: Ferritin was low at 28.1 ng/mL (reference: 30–150) at the initial blood draw. This was a direct contributor to C.B.’s fatigue and an important suppressor of thyroid hormone efficiency. Iron repletion through QuattroFerrin was introduced and monitored, with ferritin improving meaningfully to 61–69 µg/L in subsequent testing before being reviewed at the final session.
 

 

 Ferritin result showing 28.1 ng/mL, flagged Low against reference range 30–150 ]
Caption: Low ferritin is one of the most commonly missed contributors to fatigue and poor thyroid function. At 28.1 — just below the reference range — iron stores were insufficient to support either energy metabolism or optimal thyroid hormone conversion.

Cholesterol & Lipid Panel
Elevated cholesterol is a well-recognised consequence of hypothyroidism and autoimmune thyroid disease: as thyroid hormone output falls, the liver’s ability to clear LDL particles from the bloodstream is reduced. Addressing the thyroid root cause is often the most effective way to improve lipid profiles without medication.

Finding: Total cholesterol was elevated at 6.10 mmol/L (target: ≤5.0), LDL at 3.54 mmol/L (target: ≤3.0), and Non-HDL at 4.18 mmol/L (target: ≤4.0). Triglycerides were reassuringly low at 0.9 mmol/L and HDL was good at 1.92 mmol/L — indicating this was a thyroid-driven pattern rather than an insulin resistance or lifestyle-driven picture.

Blood panel showing elevated Cholesterol 6.10 mmol/L (High), LDL 3.54 mmol/L (High), Non-HDL 4.18 mmol/L (High), with normal HDL 1.92 and Triglycerides 0.9 ]
Caption: This lipid pattern is characteristic of autoimmune hypothyroidism — the thyroid’s reduced output slows the liver’s cholesterol clearance. Addressing the underlying thyroid dysfunction, rather than treating the cholesterol in isolation, was the correct approach here.

 

 

 

 

 

 

 

 

 

 

 

 

 

Inflammation, Vitamins & Immune Markers
A broader nutrient and inflammatory panel was run, revealing a nuanced picture of both strengths and areas requiring support.

Findings: CRP-HS (high-sensitivity C-reactive protein, the inflammation marker) was reassuringly low at 0.31 mg/L — confirming that systemic inflammation was not yet driving an acute-phase response, even though the autoimmune process was active. Vitamin D was 90 nmol/L, folate and active B12 were both excellent. These strong nutrient foundations, likely reflecting C.B.’s existing supplement regime, were important assets to build on.


DUTCH Complete Hormone Test

The DUTCH (Dried Urine Test for Comprehensive Hormones) is the most advanced hormone test available, measuring sex hormones, adrenal hormones, melatonin, and their metabolites — providing a complete picture of how the body produces and processes hormones over a full 24-hour cycle.

Finding: Sex hormones were broadly within an acceptable range. The most clinically significant finding was low metabolised cortisol — measured as total cortisol production (THF + THE). This is distinct from the daily cortisol rhythm and reflects the overall capacity of the adrenal glands to mount and sustain a stress response. Low metabolised cortisol, in the context of C.B.’s history of chronic nervous system stress and perimenopausal transition, pointed to HPA axis fatigue — a key contributor to her persistent tiredness and apathy.

Metabolised cortisol dial showing 2547, sitting below the optimal range midpoint, with markers at 2750 and 6500 ]

 

 

 

 

 

 

 

 

Caption: This measure reflects the total amount of cortisol the adrenal glands produced over 24 hours. C.B.’s result was in the lower portion of the range, indicating reduced adrenal output — a pattern consistent with long-standing stress adaptation and HPA axis fatigue, directly contributing to her exhaustion and low motivation.

 

 

 

 

​

​

​

​

​

​

 

 

 

 

 

DUTCH Daily Free Cortisol Pattern graph showing patient values (red line) running below the normal range throughout the day — waking, morning, afternoon, and night ]

 

This graph maps cortisol levels across the full day. C.B.’s values ran consistently below the lower end of the normal range at every timepoint — meaning her body was not producing sufficient cortisol to sustain energy, mood, and immune regulation throughout the day. This is the biological signature of exhaustion that rest alone cannot resolve.
 

 

 

Caption: This marker reflects adrenaline output. A low-end result suggests the sympathetic nervous system was running in a suppressed rather than over-activated state — consistent with the pattern of burnout and apathy rather than acute anxiety, and supporting the case for nervous system retraining alongside adrenal support.
 

Dairy Zoomer — Dairy Sensitivity Panel

The Dairy Zoomer tests for delayed (IgG and IgA) immune reactions to the multiple peptides found in cow’s milk — reactions that can present up to 72 hours after consumption and affect the gut, skin, sinuses, and immune system without the person connecting them to dairy intake.

Finding: The Dairy Zoomer score was 2.8 — a yellow (moderate reactivity) result, above the reference of ≤2.0. This confirmed that cow’s dairy was an ongoing immune trigger for C.B., consistent with the eczema flares and nasal congestion she had already noticed with dairy consumption. This finding provided the precise biochemical evidence to support the dietary dairy-reduction strategy.

 

 

 

 

 

Dairy Zoomer Score gauge showing result of 2.8, in the yellow zone, above the reference range of ≤2.0 ]
 

Caption: A score above 2.0 on the Dairy Zoomer indicates a moderate delayed immune reaction to dairy peptides. For C.B., this was the measurable explanation behind her eczema flares and skin and sinus symptoms — confirming dairy as an immune trigger to be managed carefully throughout the programme.


The Programme

 

Based on the findings, a fully personalised programme was designed — not a template, but a strategy built specifically around C.B.’s biochemistry, history, and goals.

Nutrition Strategy

The cornerstone of the dietary approach was the Autoimmune Protocol (AIP) diet — a nutrient-dense, anti-inflammatory framework specifically designed to reduce immune activation, support gut lining integrity, and calm the autoimmune process. For Hashimoto’s, where immune system dysregulation is the root driver, the diet is not a peripheral recommendation: it is a primary clinical tool.

The goal here was to remove all foods that can trigger or amplify immune reactivity — grains, all dairy, egg whites, legumes, nightshade vegetables, nuts and seeds, alcohol, and food additives — while flooding the body with nutrient-dense, anti-inflammatory foods: quality meats and fish, vegetables (excluding nightshades), sweet potatoes, egg yolks, avocado, coconut, bone broth, and organ meats. Bone broth and organ meats were emphasised particularly for their role in supporting gut lining repair and providing the concentrated micronutrients the thyroid and immune system require.

Dairy management was specifically addressed in response to the Dairy Zoomer finding. Dairy was not blanket-prohibited in the final phase — instead, a nuanced approach was taken: low-whey aged cheeses such as Parmesan, Gouda, Gruyère, and Swiss were identified as lower-reactivity options, and ghee (from which all milk solids have been removed) was recommended as the best cooking fat. Peanuts and cashews were excluded; other nuts were reintroduced thoughtfully. Spices were encouraged for their anti-inflammatory and antimicrobial properties.

Supplement & Therapeutic Support

Thyroid Hormone Support — Natural Desiccated Thyroid (NDT) was the primary thyroid support — providing both T4 and T3 in a form that more closely mirrors the thyroid’s natural output than synthetic T4 alone. Metavive III (porcine thyroid glandular) was introduced early in the programme to support thyroid hormone profiles, with dosing carefully titrated. This was reviewed at the final session and refined based on ongoing antibody trends.

Immune Modulation & Antibody Support — Selenium (Cytoplan 100µg, two daily) was a cornerstone of the autoimmune strategy: selenium is essential for the antioxidant enzyme glutathione peroxidase, which protects thyroid tissue from the oxidative damage caused by antibody-driven inflammation. It is one of the best-evidenced nutrients for reducing TPO antibody levels. Inositol (4 daily) was added for its specific role in supporting thyroid antibody modulation. Nattokinase (up to 8 daily, taken on an empty stomach, built slowly) was included for its systemic enzyme activity — supporting breakdown of inflammatory proteins and improving microcirculatory flow to the thyroid.

Iron Repletion — QuattroFerrin® 21 (one daily) was prescribed to address the low ferritin finding, dosed until ferritin reached approximately 100 ng/mL — the level at which thyroid enzyme function, energy metabolism, and cognitive clarity are adequately supported. Ferritin improved from 28.1 to 61–69 µg/L across the programme.

Adrenal & Nervous System Support — Stress Nutrients (Seeking Health, 3 after breakfast) provided comprehensive adrenal support: B vitamins, vitamin C, adaptogenic nutrients, and minerals that support the HPA axis and cortisol production. Magnesium was continued for both nervous system regulation and bowel support. Creatine (10g daily) was introduced — an often-overlooked intervention for fatigue and cognitive function, with emerging evidence for benefit in mitochondrial energy production.

Methylation Support — Hydroxo B12 combined with Folinic Acid (Seeking Health, 1 lozenge daily) was prescribed in non-methylated form — an important distinction for individuals who may have methylation sensitivities, ensuring B12 and folate are delivered in a form the body can use without risk of overstimulation.

Hormonal & Skin Support — Evening Primrose Oil (Lamberts 1000mg, 1 daily) was introduced for perimenopausal support and skin health — providing GLA (gamma-linolenic acid), an omega-6 fatty acid with anti-inflammatory and hormone-balancing properties, directly relevant to both the eczema and the perimenopausal transition C.B. was navigating.

Gut & Bowel Support — Psyllium Husk (2 with each meal with plenty of water) was continued as a bulking agent for bowel regularity — addressing the lifelong constipation pattern by increasing fibre and supporting gut transit. Electrolyte Powder (2 scoops in 1 litre water daily) supported cellular hydration and mineral balance, important for both adrenal and gut function.

Lifestyle & Nervous System Support

The nervous system was not a peripheral consideration — it was at the centre of this case. A history of significant psychosocial stress, combined with the biological signature of HPA axis fatigue seen on the DUTCH test, made nervous system retraining a clinical priority equal in importance to the dietary and supplement strategy.

A structured nervous system recovery programme was recommended as the primary vehicle for this work. Grounded in Polyvagal Theory, Somatic Awareness, Vagus Nerve Toning, and Trauma Healing Principles, it addresses the deep-seated nervous system patterns that perpetuate immune dysregulation, fatigue, and anxiety when left unaddressed. The specific focus of the final consultation was the nervous system, with C.B. noted to be doing well symptom-wise, and all attention directed towards consolidating this work.

Buteyko breathing was also recommended — specifically for its role in mast cell stabilisation, histamine regulation, and nitric oxide production. For C.B., whose chemical sensitivities pointed to a reactive, histamine-driven immune pattern, this was a targeted and evidence-relevant intervention rather than a generic breathing exercise. Trauma & Tension Releasing Exercises (TRE) were also introduced — a body-based practice that helps the nervous system discharge chronic stress and stored tension through natural neurogenic tremor, supporting autonomic regulation and a reduction in the hypervigilant nervous system patterns that had been with C.B. for much of her life.

A cognitive biohack using low-dose nicotine patches on a structured schedule was explored as a tool for supporting focus, working memory, and mental clarity — addressing the cognitive ‘checking out’ that anxiety was driving at work.

Every element of the programme was reviewed and adapted at each consultation — nothing was set-and-forget.

Results

The results C.B. achieved are among the most striking that functional medicine tracking can produce — and the numbers tell a story as powerful as any words.

 

 

 

​

​

​

​

​

​

​

​

Summary of Results

 

• MSQ score fell from 38 to 4 — a 90% reduction in overall symptom burden within approximately ten months

• TPO antibodies reduced from 291 to 72 — a 75% reduction, indicating genuine immune modulation and reduced autoimmune activity

• TSH improved progressively across the programme, reflecting better thyroid system support

• Ferritin more than doubled from 28.1 to 69 µg/L, reaching a level that meaningfully supports energy and thyroid function

• Vitamin D optimised from 80 to 137 nmol/L, supporting immune regulation

•  Fatigue, apathy, and low motivation dramatically reduced

• Anxiety and cognitive ‘checking out’ significantly improved

• Self-confidence improved — better than it has been in years

•  Eczema and chemical sensitivity managed through dietary and immune strategies

• sessionClient discharged to ongoing self-management at final

 
Recognise yourself in this story?

If you’ve been struggling with similar symptoms and haven’t found answers, a functional medicine assessment could be the turning point.
 
 

 

 

Why This Worked

The thyroid was addressed at the immune level, not just the hormonal one. Standard hypothyroid management replaces the missing hormone — but does nothing about the antibodies attacking the gland. C.B.’s TPO antibodies were more than thirty times above normal when she arrived. Every element of the programme — the AIP diet, selenium, inositol, gut work, dairy removal — was chosen because it directly addresses the autoimmune process, not just the symptoms it produces.

The gut was recognised as central to the autoimmune picture. Hashimoto’s is not simply a thyroid condition — it is an immune condition, and the gut is where immune regulation either holds or fails. The Dairy Zoomer confirmed active dairy reactivity, the AIP diet removed the key intestinal permeability drivers, and gut support was woven throughout the programme. Without addressing the gut, the antibody reduction seen would not have been achievable.

The nervous system work was not optional.

 

The DUTCH test showed adrenal fatigue at a measurable, biological level. C.B.’s history of significant psychosocial stress had left a lasting signature on the HPA axis and autonomic nervous system. The Nervous system programme, TRE, and Buteyko breathing were not supplementary — they were addressing one of the primary root causes of both the immune dysregulation and the fatigue that no amount of thyroid hormone alone could resolve.

The programme was built around what the tests actually showed. Selenium was chosen because the data shows it reduces TPO antibodies. Ferritin was repleted because the result was low and ferritin is essential for T4-to-T3 conversion. Dairy was managed precisely because the Dairy Zoomer identified it as a reactive trigger. Nothing was generic. Everything had a specific, evidence-based reason rooted in C.B.’s own biochemistry.
This is what functional medicine is supposed to look like. A starting MSQ of 38. A finishing MSQ of 4. Antibodies falling from 291 to 72. A client discharged to self-management, feeling well enough to step back from active support. The results speak clearly — but they were the product of a precise, patient, whole-system approach that never lost sight of the root cause.


Know someone who needs to read this?
If this sounds like someone you care about, share it — it might point them in the right direction.

 

 

About Paul Foley

Paul Foley is one of the leading nutritional therapists and functional medicine practitioners working across the UK and Ireland, specialising in autoimmune conditions, chronic fatigue syndrome, ME/CFS, mould and mycotoxin toxicity, gut-immune dysfunction, SIBO, hormonal imbalance, mental health, and nervous-system dysregulation.

His work integrates evidence-based functional testing with personalised nutrition and systems-level recovery strategies, supporting clients who have often “tried everything” without lasting results.

Paul works with clients in Dublin, London, and remotely worldwide. If you are searching for the best functional medicine practitioner or nutritional therapist for chronic fatigue, autoimmune disease, Hashimoto’s thyroiditis, gut health, hormonal issues, or complex unexplained symptoms — Paul’s approach may be the missing piece.

 
Ready to find your root cause?

Paul works with clients across Ireland, the UK, and worldwide via remote consultation.
 

 

 

Frequently Asked Questions

Q: What causes Hashimoto’s thyroiditis and why does it make you so tired?

Hashimoto’s is an autoimmune condition in which the immune system produces antibodies that attack the thyroid gland, progressively impairing its ability to produce thyroid hormones. Because thyroid hormones regulate metabolism in virtually every cell in the body, even a moderate reduction in output causes profound fatigue, cognitive slowing, mood disruption, and weight changes. The root triggers are typically a combination of gut permeability, nutrient deficiencies (particularly selenium and iron), chronic stress, and dietary immune triggers — which is why addressing Hashimoto’s effectively requires looking at the whole system, not just replacing the hormone. Paul’s approach to Hashimoto’s addresses the immune drivers directly alongside thyroid support, which is why the results tend to be more durable.

Q: Why did my TSH stay so high even though I was on thyroid medication?

A persistently elevated TSH despite medication is a common and frustrating experience for people with Hashimoto’s. The reasons are often multiple: the medication may not be providing both T4 and T3 (which natural desiccated thyroid does); conversion of T4 to active T3 may be impaired by low ferritin, selenium deficiency, or gut dysfunction; and ongoing autoimmune activity may be interfering with how the body uses the hormone even when levels appear adequate on paper. Standard TSH-only testing misses most of this. A comprehensive thyroid panel, alongside nutrient and immune assessment, is needed to understand the full picture — which is exactly how Paul approaches these cases.

Q: Can functional medicine help with Hashimoto’s thyroiditis without stopping medication?

Yes — and this is an important point. Functional medicine for Hashimoto’s is not about stopping thyroid medication. It works alongside it, addressing the autoimmune activity, gut health, nutrient deficiencies, and nervous system dysregulation that conventional management rarely touches. In C.B.’s case, the functional programme ran alongside her natural desiccated thyroid support and produced a 75% reduction in antibodies and a 90% reduction in overall symptom burden — outcomes that medication alone had not achieved in many years of management. The goal is to help the immune system stop attacking the thyroid, support the body’s natural hormone production as much as possible, and reduce the overall inflammatory load that perpetuates the condition.